Installations with suction lift require a good quality foot valve to avoid loss of prime - remove in-builtcheck valve.
进水口的安装需要使用一个品质优良的底阀，以避免进水口压力损失- 拆除内置式止回阀。
2
Can't check the availability of stylesheet functions, but you can check for vendor-written extension functions built into the processor?
不能检查样式表函数的可用性，但是可以检查处理程序中内置的厂商编写的扩展函数。
3
The software then uses Bluetooth, the short-range radio technology built into many mobile phones, to check whether any friends or other members with similar interests are within 20 metres.